Automatic corn press



April 23, 1968 E. F. KELLEY ET AL 3,379,143

AUTOMATIC CORN PRESS Original Filed Feb. 10, 1964 5 Sheets-Sheet 1 I 112I 50 r/s-ua [2Q /20-/20, MA 48 R921,

INVENTORS.

Edwin F. hel/eg BY Frank J. Thomas April 23, 1968 E. F. KELLEY ET AL3,379,143

AUTOMATIC CORN PRESS Original Filed Feb. 10, 1964 5 Sheets-Sheet t:

Flig4.

INVENTORS. Edwin F. Kelley BY Frank J. Thamas J arm/a 3.

A ril 23, 1968 E. F. KELLEY T AL 3,379,143

AUTOMATIC CORN PRESS Original Filed Feb. 10, 1964 5 Sheets-Sheet 5 April23, 1968 E. F. KELLEY ET AL AUTOMATIC CORN PRESS 5 Sheets-Sheet OriginalFiled Feb. 10, 1964 130 INVENTORS.

fawin E Kelley BY Frank J. Thomas m5 AUTO.

April 23, 1968 E. F. KELLEY ET AL 3,379,143

I AUTOMATIC CORN ITRESS Original Filed Feb. 10, 1964 5 Sheets-Sheet 5 M6 1/59 (/54 E0" I56 L146 mvfN'roRs.

Edwin E Ke le g I BY Frank J. Thon /as 3,379,143 AUTGMATIC CORN PRESSEdwin F. Kelley, Kansas City, Mo., and Frank J. Thomas, Overland Park,Karts, assignors, by mesne assignments, to Manley, Inc, Kansas City, Mo,a corporation of Missouri Original application Feb. 10, I964, Ser. No.343,603. Divided and this application Nov. 2?, 1966, Ser. No.

29 Claims. (til. 107-14) ABSTRAKIT F THE DHSCLOSURE A pair ofmaterial-feeding tubes are associated with an extrusion head, each tubehaving a material inlet spaced from the head for receiving dough whichis ultimately forced intothe head and extruded therefrom. A rotary valveis utilized to alternately communicate the tubes with the head toprovide continuous extrusion. A reciprocating ram is disposed in eachtube for loading the latter and forcing the loaded dough into the head.Loading is effected in a particular tube by reciprocating the ramthereof across the inlet to progressively load the tube a wad at a timeuntil a mass of dough is accumulated, whereupon a continuous forwardstroke of the ram commences to pack the dough against the closed valve,the latter being open to the other tube at this :time which is in itsextrusion phase. After packing, the valve is shifted to open that tubeto the head and the ram thereof is then driven under high pressure toextrude the packed dough, during which time the other ram is caused toundergo its loading phase.

This is a division of our co-pending application Ser. No. 343,608, filedFeb. 10, 1964, and entitled, Automatic Corn Press (now abandoned).

This invention relates generally to extruding machines and, morespecifically, to improvements in apparatus for extruding dough orsimilar substances.

The apparatus to be described hereinafter is used primarily in theprocess of manufacturing corn chips by forcing a prepared dough throughan extrusion die. In order to obtain maximum efficiency and output fromthe extruder, it is requisite that the extrusion head be continuouslyfed with the material to be extruded. Furthermore, especially when doughor similar substances are to be extruded, it is also necessary that thematerial be packed to the desired density to form a homogeneous batch orbody prior to extrusion.

It is, therefore, the primary object of this invention to provide meansfor continuously feeding an extrusion head with packed dough or similarsubstances to be extruded.

It is another object of this invention to provide a pair of materialfeeders for an extrusion head, one of the feeders being employed to loadthe material while the other feeder drives loaded material into the headand to provide means for alternating operation of the feeders so thatcontinuous loading and extruding will be effected.

It is another object of this invention to provide a machine forprogressively accumulating material to be extruded, compressing theaccumulated material to pack it into a composite mass, and graduallypressing the packed mass into an extrusion head.

Another object of this invention is to provide a feeder tube and ram foran extrusion head that will progressively load the tube with material tobe extruded and then transfer the loaded material into the head.

Still another object of this invention is to provide a feeder tube andram as aforesaid in combination with a valve for the tube which blocksflow of material into d States Patent 0 M 3,3?9J43 Patented Apr. 23,1968 the head during loading of the material, permitting packing of theloaded material against the valve by the ram prior to transfer thereofinto the head upon opening of the valve.

Yet another object of this invention is to provide apparatus as setforth in the last-mentioned object that will increase the force exertedon the material after packing to a higher level for transfer of thematerial into the head.

It is still another object of this invention to provide a rotary valvefor an extrusion head for use in alternately communicating materialfeeders with the head, and which permits packing of material against thevalve by the feeder that the valve is blocking.

Other objects will become apparent as the detailed description proceeds.

In the drawings:

FIGURE 1 is a side elevational view of the apparatus of the instantinvention;

FIG. 2 is a top plan view of the apparatus;

FIG. 3 is an irregular, sectional view taken along line 33 of FIG. 2showing the rotary valve of the instant invention with the extrusion dieremoved from the extrusion head;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a diagrammatic representation of the apparatus showing thehydraulic cylinders, hydraulic valves, and the limit switches andpressure sensitive switches employed by the control circuitry;

FIG. 6 is an electrical schematic diagram of the control circuitryshowing all components thereof de-energized and deactivated;

FIG. 7 is an electrical schematic diagram identical to FIG. 6 exceptthat the components thereof are shown in energized and activated statescorresponding to extrusion by one ram and advancement of the other ramtoward the extrusion head during loading by the other ram;

FIG. 8 is a fragmentary, electrical schematic showing one ram extrudingwhile the other ram is retracting during the loading mode;

FIG. 9 is an electrical schematic showing completion of the extrusioncycle by one ram and advancement of the other ram toward the dough packsubsequent to its loading cycle;

FIG. 10 is a fragmentary electrical schematic showing the previouslyextruding ram now retracting from the extrusion head while the other ramis commencing extrusion; and

FIG. 11 is a diagrammatic and schematic representation of means foralternately feeding the two tubes with material to be extruded.

Mechanical components of the extruder Referring particularly to FIGS. 1,2 and 5, the reference numeral '20 designates a housing containing thepower supplies and control circuitry for the extrusion machine. Themachine proper is mounted on housing and comprises an extrusion head 22and a pair of tubes 24 and 26 communicated with the head. Tubes 24 and26 have a pair of reciprocable rams 28 and 30, respectively, disposedtherein. (It should be understood that the dispositions of the rams 28and 30' shown in the diagrammatic representation of FIG. 5 are not thesame as the positions of the rams illustrated in the elevational viewsof FIGS. 1 and 2.)

The head 22 includes a generally cylindrical, hollow body 32 and anextrusion die 34. Material is extruded from the head through a series ofcircumferentially spaced slots 36 in the die. A ring gear 33 is coupledwith a knife (not shown) which cuts the extruded ribbons intopredetermined lengths. Ring gear 38 is driven by a motor 40 operablycoupled with a pinion 42, the latter being engaged with ring gear 33.

Tubes 24 and 26 have inlet ports 44 and 46 therein, respectively, whichreceive the material to be extruded from a hopper 48. Hopper 48 hastherewithin a partition 50 which is inclined from its center toward theports 44 and 46 so that material may be alternately directed to theports in a manner to be hereinafter described.

Tubes 24 and 26 have associated therewith hydraulic cylinders 52 and 54respectively. Cylinder 52 is coupled with ram 28 in tube 24 by a piston(not shown) and piston rod 56. The ram 30 in tube 26 is coupled withcylinder 54 by a piston 58 in cylinder 54 and its piston rod 68. Itshould be appreciated that the rams slide within their tubes, the outersurfaces of the rams being mated with the inner surfaces of the tubes sothat the inlet ports 44 and 46 are sealed when the rams are inunderlying relationship thereto.

Support structures 62 rigidly mount a pair of rods or guides 64 and 66in alignment with rams 23 and 30 respectively. Rams 28 and 30 carrysleeves or tubular, cambearing members 68 and 70 respectively. Themembers 68 and 70 slidably receive guides 64 and 66. Member 68 carries acam '72 which is operably associated with limit switches 74-74, 76,78-78. Similarly, member 70 carries a cam 80 which is opera-blyassociated with limit switches 82-82, 84, and 86-86.

With reference now to FIGS. 1-5, it may be seen that body 32 ofextrusion head 22 has therewithin a rotary valve Valve 88 comprises agenerally cylindrical housing 90 having an entrance 82 in the side ofthe housing, and an exit 94 in the base of the housing. Body 32 has apair of inlets 96 and 98 in the side thereof registered with the ends oftubes 24 and 26, respectively, and an outlet 100 in the base of thebody. A vertical shaft 192 is rigid with valve 83, such shaft extendingthrough an opening 104- in the top of body 32 and being journalled onthe body by bearing assembly 106. A bearing assembly 108 journals thelower portion of housing 90 for rotation within the outlet 100 in thebase of body 32.

It may be appreciated that rotation of shaft 102 rotates valve 88 abouta vertical axis through the shaft and swings entrance 92 so that theentrance may be aligned with inlet 96 or inlet 98. This permits passageof material from one of the tubes 24 or 26 through the valve and ontoextrusion die 34 through outlet 100 by Way of exit 94. Entrance 92 andexit 94 are communicated by a longitudinally curved, tubular member inthe form of a 90 elbow 110 which defines a passage for flow of materialfrom the entrance to the exit.

A crank arm 112 is coupled with shaft 102 and is actuatable by ahydraulic piston and cylinder assembly 114. Piston stem 116interconnects the end of crank arm 112 remote from shaft 102 withassembly 114. Limit switches 118-118 and 128-120 are disposed foractuation by crank arm 112 at the ends of its path of travel. It may benoted that a vertically extending pin 122 is disposed on the crank armin spaced relationship to the axis of rotation thereof, pin 122 beingengageable with a limit switch 124 for actuating the latter midway inthe path of travel of the crank arm. (Switch 124 may be seen in FIGS.and 11).

Hydraulic system and electric control circuitry Referring to FIGS. 5-10it may be seen that the hydraulic controls for the extruder comprisehydraulic valves 126, 128, 138 and 132. Valve 126 is controlled bysolenoids 126 and 126 coupled therewith. Valve 128 is spring-biased intothe neutral position shown in FIG. 5 and is operably coupled with a pairof solenoids 128 and 128", such solenoids being employed to move valve128 to its operative positions. In similar fashion, valve 130 iscontrolled by solenoids 139 and 130" and valve 132. is operated bysolenoids 132 and 132". Both valves 130 and 132 are spring-biased so aso be no mally maintained in the neutral position, valve 132 being shownin FIG. 5 in such neutral position, while valve is illustrated in itsoperative position corresponding to energization of solenoid 130".

Hydraulic lines 134 operably couple piston and cylinder assembly 114with valve 128, actuation of solenoids 126' or 126 effecting movement ofvalve 126 to, in turn, cause longitudinal shifting of piston stem 116.Piston stem 116 is shown in its extended position corresponding toenergization of solenoid 126', at which time crank arm 112 is operablyengaged with limit switch 118-118 to effect communication of valve 88with tube 24. This is illustrated in FTG. 5 and is the positions ofthese components when material is being extruded from tube 24 by ram 28and hence passed through the valve to the extrusion die. It should beappreciated that energization of solenoid 126 will swing crank arm 112until the same engages limit switch 128-120, this position correspondingto extrusion by ram 30.

Valve 128 is coupled with cylinder 52 by hydraulic lines 136. In theFIG. 5 illustration this valve is inoperative for reasons to be fullyexplained hereinafter. Valve 130 is coupled with cylinder 52 byhydraulic line 138, valve 139 being schematically illustrated asdisposed to permit passage of fluid from the pressure side or fluidsource to cylinder 52. This effects driving of ram 28 to extrudematerial from tube 24.

Ram 30 in tube 26 is shown in FIG. 5 at rest during loading of materialinto tube 26. The loading operation will be described fully hereinafter,it being sufficient at this juncture to note that valve 132 is coupledwith cylinder 54 by hydraulic lines 140 and valve 130 is coupled withcylinder 54 by hydraulic line 142. The hydraulic fluid for ope-ratingthe cylinders 52, 54 and 114 may be supplied by any suitable source, thedesign and constructional details thereof being widely known andunderstood in the art. For this reason, the hydraulic system in itsentirety is not shown in the drawings. It should be understood, however,that it is desired to supply valve 130 with fluid under a relativelyhigh pressure since this valve controls fluid flow into cylinders 52 and54 during the extrusion phases of the rams when high driving power isrequired. On the other hand, lower fluid pressures are preferred forvalves 126, 28, and 132.

The circuitry for controlling the energization of the various hydraulicvalve solenoids is shown in FIGS. 6-10. The limit switches associatedwith the rams and the valve are there illustrated in schematic form. Itshould be understood that limit switches designated by a singlereference character are single-pole switches, while those limit switchesdesignated earlier in this specification by double reference characters(an unprinted and a primed notation) are double-pole switches.Therefore, these latter limit switches are actually two switches in oneresponsive to a single actuator arm.

Referring momentarily to FIG. 1, it may be noted that an actuator arm 83is operably coupled with limit switch 82-82, the limit switches 84 and86-86 being provided with actuator arms 85 and 87 respectively. Theseactuator arms 83 85 and 87 are responsive to engagement by cam 80 asmember 70 slides along guide 66 during movement of ram 38. When cam 80strikes one of these actuator arms the corresponding limit switch ismoved from its normal position to its operated position for the periodof time that the cam remains in engagement with the arm. Similarly, cam72. controls the operational state of limit switches 74-74, 76, 78-78associated with ram 28, and crank arm 112 controls the operational stateof limit switches 118-118 and 129-128. The operation of limit switchessuch as these being well-known and used in the art, further explanationin this specification is unnecessary, it being understood that theselimit switches control the operation of valve 88 and rams 28 and 329through the use of control circuitry to be fully described in theparagraphs to follow. 1

In FIG. 6 the various limit switches aforesaid are shown in their normalstates prior to actuation thereof. It may be noted that the solenoidsfor controlling the hydraulic valves appear in FIG. 6, the solenoidsbeing operably coupled with the limit switches by a system of relays andswitching circuitry. It should be understood that the relay coils of therelays are designated by numerical reference characters, each switchresponsive to a given relay coil being designated by a numericalreference character identical to the numeral used for the coil butfollowed by the letter a, b, c or d. This system of notation for therelay coils and switches responsive thereto will become clear in theparagraphs to follow.

Lines 144 and 146 represent connection points for a suitable source ofelectrical power. A single-pole, threeposition switch 1- .8 is manuallyoperable and selects the operational state of the circuitry. When theswitch is in the position shown, the circuitry is coupled with the powersource and renders the extruder responsive to automatic control by thecircuitry. The manual position provides a connection for push buttonswitches (not shown) which may be added to the circuitry to providemanual override of the automatic functions for use during starting ofthe machine, cleaning thereof, etc.

In FIG. 6 it may be seen that the circuitry comprises relay coils 159,152, 154, 156, 158 and 16%. All of these relay coils have one electricalside thereof connected with line 146. Coil has associated therewith anormally open switch 158a and a normally closed switch 15%.

Coil 152 has associated therewith a normally open switch 152a. Relaycoil 154 is operably coupled with a normally open switch 154a, anormally closed switch 154b, a normally closed switch 154a, and anormally open switch 154d. Coil 156 is coupled with a normally openswitch 156a and a normally closed switch 156:). Coil 153 has a normallyopen switch 158a responsive thereto. Coil 160 is operably associatedwith a normally closed switch 169a, a normally open switch 16%, anormally closed switch 1600, and a normally open switch 16%;].

The control circuitry also includes a pair of timers 162 and 164. Timer16."; is operably coupled with a normally open switch 162a and timer 164is operably coupled with a normally open switch 164a. It should beunderstood that each timer and its associated switch may be a unit suchas a time-delay relay or an electronic timer device. Each timer operatesto close its associated switch a preset period of time subsequent toenergization of the timer and maintains the switch in the closedposition as long as the timer remains energized.

The control circuitry also employs a pair of pressuresensitive,single-pole double-throw switches 166 and 168. In FIG. 5 it may be seenthat these switches 166 and 168 are coupled, respectively, withhydraulic lines 135 and 140. Each of the switches is actuatable by apredetermined amount of pressure in the corresponding hydraulic line andis shown in FIG. 6 in the position corresponding to fluid pressures lessthan this predetermined amount. \Vhen the predetermined pressure isreached, the switch moves to its other position until such time as thepressure subsides.

In FIG. 11 apparatus for alternately feeding the inlet ports 44 and 46of tubes 24 and 2-5 with material to be extended is shown indiagrammatic form. A collector 1'70 disposed above hopper 48 receivesthe material and transmits the same to a rotatable pipe or chute 172. Apair of solenoids 174 and 176 is operably coupled with chute 172 formoving the latter from the position shown, in which the chute directsmaterial into port 46, to a position where the chute directs materialinto port 44.

A stepper relay 178 operates a rotary switch element 180 which engagesany diametrically opposed pair of contacts 182, 184, 186 and 188. Lines190 and 192 supply relay 178 with electrical power through limit switch124 interposed in series with line 19%.

It may be remembered that a pin 12 2 extending from crank arm 112actuates limit switch 124 momentarily midway in the path of travel ofcrank arm 112 between limit switches 118-118 and 129-120. This momentaryclosing of switch 124 energizes relay 178 to rotate element 180 to thenext position. Successive momentary energizationof relay 178 thuseffects continual rotation of element 180 step-by-step to alternatelyenergize solenoids 174 and 176.

Operation Before a detailed discussion of the operation of the instantinvention is undertaken, it is instructive to first become familiar withthe scheme of operation in a general sense and with the particularprocess being carried into effect by the apparatus of this invention.

The two tubes 24 and 26 are provided so that continuous feeding ofmaterial into the extrusion head will be effected. To this end, whileone ram is forcing material down its tube, through the rotary valve, andthence into the extrusion die, the other ram is reciprocated in its tubebetween defined limits across the corresponding inlet port to loadmaterial into the tube. Thus, in essence, the operation of the inventioncomprises forcibly feeding material accumulated in one tube into theextrusion head while material is being accumulated in the other tube forsubsequent extrusion.

The foregoing may be readily appreciated by viewing FIG. 5. In thisfigure, as explained above, ram 23 is shown at the commencement of itsextrusion phase while ram 30 is shown at rest during loading of tube 26.Looking first for the moment at tube 24 and ram 28 only, it may be seenthat cam 72 associated with ram 28 is just to the left of limit switch76. Ram 28 will continue movement longitudinally of tube 2- andleftwardly as viewed in the figure until cam 72 strikes limit switch74-74.

Looking now at the operation of ram 36 during the aforesaid extrusionphase of ram 28, it may be seen that earn associated with ram 30 willstrike limit switch 84 when the ram commences movement toward theextrusion head. Switch 84, through its associated control circuitry,halts the forward movement of ram 39 when cam 89 strikes the switch andeifects retracting movement of the ram back toward limit switch 86-35.Thus, limit switches 84 and 36-36 define the limits of reciprocation ofram 30 and cause the ram to follow a path of travel back and forthacross inlet port 46 (the inlet ports are not seen in the diagrammaticrepresentation of PEG. 5).

It may readily be appreciated that the movement of ram 3i) back andforth across the inlet port will push wads of dough or other material tohe extruded toward the extrusion head a short distance duringadvancement of the ram, and that during retraction thereof, apredetermined quantity of dough will be permitted to flow into the tubein front of the ram for subsequent forward movement when the ram is nextadvanced. To facilitate this action, the reciprocating ram 30 dwells ormomentarily stalls when its cam 8d strikes limit switch 86-86 to permitfiow of dough into the tube.

By the time the extruding ram 28 has reached its forwardmost position,the reciprocating ram 36 has loaded a number of wads of dough into thetube to form a dough batch for subsequent extrusion. When the cam 72 ofram 28 strikes limit switch 7474 the control circuitry effects forwardmovement of ram 30 toward the head past limit switch 84 to pack thebatch into a composite mass. Thus, limit switch 84 is renderedineffective by the control circuitry and will not stop ram 30,permitting the ram to execute the packing function.

It is evident that the packed batch of dough in tube 26 will increasethe resistance to the movement of ram 30 toward the head. This increasein resistance is reflected in the hydraulic system; hence, pressuresensitive switch 163 will be actuated when the pressure within thepacked, composite mass of dough reaches a predetermined value. Actuationof the pressure sensitive switch momentarily halts further forwardmovement of ram 30 and, through associated circuitry, actuates pistonand cylinder assembly 114 to rotate valve 88 into alignment with tube26. When the valve becomes aligned with tube 26 it strikes limit switch120426 and commands ram 3% to begin the extrusion phase while ram 28 isretracted to commence reciprocation and loading of its tube with dough.Therefore, the mass of dough that was packed against the valve by ramSt? is now forced into the extrusion head.

A complete cycle of operation will now be described in detail. As statedpreviously, FIG. 6 shows the various electrical components in theirdie-energized or inactivated states. It will be assumed initially inthis discussion that ram 23 is extruding and that ram 3d is justcommencing forward movement during its loading phase. This initial setof conditions is shown in FIGS. and 7 wherein FIG. 5 shows the relativelocations of the rams and the positions of. the hydraulic valves, andFIG. 7 shows the positions of the various switching devices.

With reference to FIG. 7, it may be seen that the following electricalis circuit is actuating valve 139 to drive ram 28 towards the extrusionhead 22: From line 144 to limit switch 74, along conductor 194 to limitswitch 118, and hence through solenoid 130" to line 146. It may thus beappreciated that the engagement of cranl; arm 112 with limit switch113-113 closes an electrical circuit through solenoid 130 to ellcctforward driving of ram 28.

Valve 33 is maintained in the FIG. 5 position by the followingelectrical circuit: From line 144 to relay switch 1540, along conductor1% to solenoid 126', and hence through the solenoid to line 146. It maybe noted. that relay switch la is normally open but is now closed due tothe energization of the associated relay coil 154. The energizingcircuit for coil 154 is traced as follows: From line 144 to limit switch74, through relay switch 15411 to the lower contact of pressuresensitive switch 166, and hence through relay switch 169a and relay coil154 to line 146. Furthermore, a circuit in shunt with relay switch 154dexists from limit switch 74 through the now actuated pressure sensitiveswitch 166.

It should be understood, and will become clear in the paragraphs tofollow, that the actuation of pressure sensitive switch 166 initiallyenergized coil 154, the set of contacts 154d serving as a holdingcircuit to maintain coil 154- energized even though pressure sensitiveswitch 166 should become inactivated for any reason, such as an airbubble or slight void in the dough pack which would effect a loss ofpressure. Thus, completion of the extruding phase of ram 28 is assured.

Referring now to the operational state of ram 30 as portrayed by FIGS. 5and 7, it may be seen in FIG. 7 that timer 164 is energized because ofthe actuation of limit switch 86-86 by the cam 81, associated with ram36). FIG. 7 shows the status of timer switch 164a after timer 164 hastimed out and reveals that switch 164a is now closed by the action oftimer 164 to momentarily create the following electrical circuit: Fromline 144 to relay switch 15% (initially closed), along lead 199 to thenow activated limit switch 86, through timer switch 164a and solenoid132', and relay coil 156 in parallel therewith, to line 146. Solenoid132 is thus energized after timer 146 times out, resulting in actuationof hydraulic valve 132 to move the valve leftwardly as viewed in FIG. 5to direct fluid flow into the cylinder 54 in the proper direction toeffect advancement of ram 30.

It should be appreciated that limit switch 86 only momentarily suppliescurrent to relay coil 156 and solenoid 132, since immediately uponenergization of coil 156, its contacts 156a close and 156i: open (asshown in FIG. 7). Coil 156 thus latches through its own cont-acts 156aand creates the following holding circuit to maintain solenoid 132'energized: From the line 146 to solenoid 132, along lead 282 to relayswitch 156a, along lead 204 to limit switch 84, limit switch 74 to relayswitch 160:: through pressure sensitive switch 168 and along lead 2% tolimit switch 82', and hence to line 144. Therefore, once cam 80 becomesdiseng" "ed with limit switch 86-86 upon forward all movement of ram 30,it may be seen that the return of switch 86 to its normal position hasno effect on the operation of solenoid 132'. The return of switch S6 tothe normal position by forward advancement of ram 30 decnergizcs timer164, thereby resetting the same.

Ram 39 continues advancement toward head 22 until cam 8t strikes limitswitch 84, whereupon ram 30 is then retracted by operation of thecontrol circuitry as depicted in FIG. 8. FIG. 8 is a fragmentary view,the remainder of the circuitry being in the same state as shown in H6.7. It may be seen that PlG. 8 is broken away at leads 202, 2%4 and 296and at lines 144 and 146 immediately leftwardly of their connectionswith relay switch 156.) and solenoid 132, respectively.

Engagement of cam 81 with the actuator arm of limit switch 84establishes the following electrical circuit: From line 144 to limitswitch 82, along lead 2&8 to pressure sensitive switch 168, throughrelay switch 169a, and limit switch 74 to the now actuated limit switch84, and hence along lead 210 through solenoid 132" to line 146. Thisenergizes solenoid 132 to shift hydraulic valve 132 rightwardly asviewed in FIG. 5 to align the fluid source and reservoir with hydraulicconduits to effect retracting movement of ram 30 away from head 22.Solenoid 132. is maintained energized after cam leaves limit switch 84due to a holding circuit that is established while switch 84 isactivated. This holding circuit is initiated since solenoid 132 andrelay coil 158 are connected in parallel, such circuit being traced asfollows: From line 14-ithrough relay switch 156b along lead 212 to limitswitch S6, and hence through the now closed contacts 156a to relay coil158 and line 146.

Ram 30 will continue to advance and retract across the inlet port 46 oftube 26 to progressively load material into tube 26 in the manner asdescribed above until ram 28 finishes its extrusion phase. At suchfinish, cam 72 associated with ram 28, strikes limit switch 74-74 andthe condition of the control circuitry is then altered to that as shownin FIG. 9. It may be seen that activation of limit switch 74' breaks thepower circuit previously existing through switch 74' and conductor 194to solenoid Therefore, ram 28 is halted as it approaches the inlet 96 ofhead 22.

Simultaneously, actuation of limit switch 74 establishes the followingelectrical circuit shown in FIG. 9: From line 144 to limit switch 82',along lead 214 to pressure sensitive switch 168, through relay switch160a to the now activated limit switch 74, and along lead 216 throughrelay coil 156 and solenoid 132' in parallel therewith to line 146.Energization of solenoid 132' causes ram 39 to immediately commenceadvancement toward head 22 regardless of its existing position.Furthermore, ram 30 will continue to advance toward the extrusion headeven though cam 80 strikes limit switch 84 because the circuit throughthe now activated limit switch 74 eifectively lay-passes limit switch.84 and negative its control function. Ram 30 is thus advanced forwardlyinto the dough batch to pack the batch into a composite mass againstvalve 88.

' Once ram 36 encounters a predetermined amount of resistance, pressurein hydraulic lines will rise and actuate pressure sensitive switch 168.In FIG. 9 it may be seen that actuation of switch 168 will break thepower circuit through solenoid 132' and stop the advancement of ram 30.Furthermore, actuation of switch 168 establishes the followingelectrical circuit which effects rotation of valve 88: From line 144 tolimit switch 82, along lead 214 to the now activated pressure sensitiveswitch 168, and through relay switch 154th to relay coil and line 146.Energization of relay coil 160 reverses the positions of its associatedswitches from that as shown in FIG. 9 to create the following circuit ofinterest: along line 144 to junction point 218 through now closed relayswitch 160!) and along lead 220ito solenoid 126", and

hence to line 146. Energization of solenoid 126" actu-.

ates piston and cylinder assembly 114 to rotate the Valve into alignmentwith tube 26.

When valve 88 moves into alignment with tube 2.6, crank arm 112 engageslimit switch 120-120 and the status of a portion of the circuitry ofinterest is then as shown in the fragmentary schematic of FIG. 10. Itmay be seen in FIG. 10 that limit switch 120 has created the followingcircuit: From line 146 to solenoid 130', through switch 1 9' along lead2% to limit switch 82', and hence to line 144. Energization of solenoid130 aligns the hydraulic conduits of valve 130 in a manner to effectdriving of ram 30 toward the head to extrude the packed dough.

Simultaneously with the commencement of the extrusion phase of ram 30,limit switch 12s elfects retracting movement of ram 23 so that the samemay commence its loading phase. This action may be seen by viewing FIG.6, wherein it is apparent that closure of switch 129 will energizesolenoid 128" since limit switch 74 is initially in its activatedposition with cam 72 resting against its actuator arm. Furthermore,since solenoid 12S" and relay coil 152 are connected in parallel, coil152 will also become energized and create a holding circuit through itsown contacts 152a to maintain solenoid 12S energized after cam 72 movesoff of the actuator arm of limit switch 74 and returns this switch toits inactivated position.

The operation of the control circuitry in eifecting reciprocatingmovement of ram 28 through the use of hydraulic valve 128 is similar tothat as described above for ram 38 and, therefore, will not be repeatedherein. It should be understood that the left and right-hand portions ofthe schematic drawings of FIGS. 6, 7 and 9 are essentially identical;therefore, those skilled in the art may readily trace the operation ofthe circuitry in reciprocating ram 23 by reference to the abovedescription for ram 39. Accordingly, the operation of the circuitryduring the extrusion phase is correspondingly similar to the operationas above described for ram 23.

With reference now to FIG. 11, a brief discussion is in order regardingthe control of the flow of dough into the inlet ports 44 and 45.Attention is directed to FIG. 5 where it may be seen that the pin 3.22on crank arm 112 strikes the actuator arm of limit switch 124 midwayduring rotation of the valve as discussed above. This momentaryactuation and release of switch 124 momentarily energizes stepper relay178 to rotate element 18%.

More specifically, it may be seen in FIG. 11 that the state of thecircuitry is shown with solenoid 176 energized. However, the next timeswitch 12 3 is momentarily closed, element 139 will no longer provideelectrical continuity between contacts 186 and 182 but will move to anew position electrically interconnecting contacts 188 and 184. Thislatter connection energizes solenoid 174 and shifts chute 172 to theleft-hand position in alignment with inlet port 44. In this manner, thechute is caused to oscillate back and forth during rotation of valve 88so that the dough will flow into the tube corresponding to the pistonunder reciprocation.

It should be understood that the hydraulic system set forth in FIG. 5 isadvantageously provided with both a low and a high pressure fluidsource. The low pressure source is supplied to the traverse valves 128and 132 and may also be employed in the operation of valve 126. Valves12-5 and F132 and their associated hydraulic circuitry should beconstructed and arranged to provide relatively hi h speed reciprocationof the piston.

The high pressure source is connected to feed valve 130 so that, whenthis valve is actuated to apply fluid pressure to one of the cylinders52 or 54, the ram will be driven forwardly under considerable power toeffect the extrusion of the dough. Valve 13-0 and its associatedhydraulic circuitry should be arranged so that high power, butrelatively low speed, will be applied to the driven ram, moving thelatter at a fixed rate of speed regardless of the consistency of thedough. Attention is directed to the fact that the packing phase of eachram subsequent to loading of its associated tube will thus be effectedby the higher speed, lower power, hydraulic system, the higher powerlevel being employed only during the extrusion phase.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In an extruder:

an extrusion head having a hollow body;

a tube having one end thereof registering with said body and providedwith a material inlet port spaced from the body;

a normally closed valve disposed to block passage of material from thetube into the body;

a ram reciprocable in the tube toward and away from said body;

a prime mover connected with the ram for actuating the latter; and

structure coupled with the prime mover for controlling the latter tofirst repeatedly reciprocate the ram across said port and therebyprogressively load the tube with material between said port and saidbody and to thereupon, after a predetermined period of loading time,drive the ram continuously toward said body and thereby transfer thematerial from the tube into the body upon opening of the valve.

2. The invention of claim 1, said structure having mechanism operablesubsequent to loading of the tube and prior to continuous driving or"the ram for effecting advancement of the ram toward the body to pack thematerial against the valve.

3. In an extruder:

an extrusion head having a hollow, material-receiving body provided witha material inlet;

a valve normally closing said inlet; and

a material feeder for the head including:

a tube registering with said inlet and provided with amaterial-receiving port spaced from the head;

a ram reciprocable in the tube toward and away from said inlet;

a prime mover connected with the ram for actuating the latter;

control means coupled with the prime mover for repeatedly reciprocatingthe ram across said port to progressively load the tube with materialbetween said port and said inlet, said control means having structureoperable after a predetermined period of loading for driving the ramcontinuously toward said inlet, whereby to move the material in the tubetoward the inlet; and

means connected with the valve for actuating the latter to open theinlet subsequent to loading of the tube and prior to continuous drivingof the ram.

4. In an extruder:

an extrusion head having a hollow body;

a tube having one end thereof registering with the body;

a ram reciproc-able in the tube between said one end of the latter andthe opposite end thereof, said tube having a material inlet disposedbetween said ends whereby, upon reciprocation of the ram across theinlet, material entering the latter will be progressively loaded in thetube between the inlet and the body;

a normally closed valve disposed to block passage of the material fromthe tube into the body during load- 111g;

structure operabiy coupled with the ram for controlling the latter todrive the same toward the body after loading of the tube with material,whereby to pack the latter against the valve;

apparatus coupled with the valve for opening the latter after saidpacking of the material whereby, upon continuation of said drivin of theram toward the body, the material is transferred from the tube into thebody; and

means responsive to a predetermined position of the ram in proximity tothe body for discontinuing its continuous movement toward the body andeffecting a successive cycle of reciprocating movement.

5. The invention of claim 4', and means increasing the force exerted onthe material during transfer to a higher level than the force exertedthereon during packing.

6. The invention of claim 4, and means responsive to opening of thevalve for increasing the force exerted on the material during transferto a higher level than the force exerted thereon during packing.

7. In an extruder:

an extrusion head having an hollow body;

a tube having one end thereof registering with the body;

a ram reciprocable in the tube between said one end of the latter andthe opposite end thereof, said tube having a material inlet disposedbetween said ends whereby, upon reciprocation of the ram across theinlet, material entering the latter will be progressively loaded in thetube between the inlet and the body;

a normally closed valve disposed to block passage of the material fromthe tube into the body during loadstructure operably coupled with theram for controlling the latter to repeatedly reciprocate the ram acrossthe inlet to eifect said progressive loading of the tube with material,and to drive the ram toward the body after loading of the tube withmaterial, whereby to pack the latter against the valve; and

apparatus coupled with the valve and responsive to a predetermined levelof pressure in the packed material for opening the valve whereby, uponcontinuation of said driving of the ram toward the body, the material istransferred from the tube into the body.

8. In an extruder:

an extrusion head having a hollow body;

a pair of tubes each having one end thereof registering with the body;

a ram reciprocable in each tube respectively between said one end of thelatter and the opposite end thereof, each tube having a material inletdisposed between said ends whereby, upon reciprocation of the ramsacross the inlets, material entering the latter will be progressivelyloaded in the tubes between the inlets and the body;

a valve movable selectively to a closed position with respect to onetube, blocking passage of the material from the one tube into the bodyduring loading of the one tube, and an open position with respect to theother tube to permit passage of loaded material in the other tube fromthe latter into the body;

means coupled with the valve for opening the latter with respect to theone tube and thereby close the same with respect to the other tube afterloading of the one tube with material; and

structure operably coupled with the rams for controlling the latter torepeatedly reciprocate one of the rams when its corresponding tube isclosed by the valve and simultaneously drive the other ram to ward thebody, whereby material is transferred to the body alternately from thetubes, and whereby each ram reciproeates to load its tube while theother ram transfers loaded material into the body.

9. The invention of claim 8, said structure being responsive to apredetermined position of the driven ram in proximity to the body fordiscontinuing its movement toward the body and alternating the operationof the rams.

10. The invention of claim 8, said structure having mechanism operablesubsequent to loading of each tube and prior to transfer of the loadedmaterial into the body for advancing the ram of the loaded tube towardthe body to pack the material against the valve, said means opening thevalve with respect to the loaded tube after said packing of the materialagainst the valve.

11. The invention of claim 10, said means being responsive to apredetermined level of pressure in the packed material for opening thevalve with respect to the loaded tube.

12. The invention of claim 10, and means increasing the force exerted onthe material during transfer to a higher level than the force exertedthereon during packmg.

13. The invention of claim It}, and means responsive to opening of thevalve with respect to the loaded tube for increasing the force exertedon the material during transfer to a higher level than the force exertedthereon during packing.

14. In an extruder:

an extrusion head having a hollow, material-receiving body provided witha pair of material inlets;

first and second tubes each registering with a corresponding inlet andhaving a material-receiving port therein spaced from the correspondinginlet;

a first ram in said first tube for movement longitudinally thereof;

a second ram in said second tube for movement longitudinally thereof;

valve means in the body closing the inlet associated with said firsttube and movable out of closing relationship therewith to a dispositionin closing relationship with the inlet associated with said second tube;

means operably coupled with said first ram for reciproeating the latter,said reciprocating means including control means maintaining the path oftravel of the first ram between a first position where the port of thefirst tube is between the first ram and the body and a second positionwhere the ram is between the port and the body;

means operably coupled with said second ram for driving the same towardthe body to a location adjacent the corresponding inlet, wherebymaterial in the second tube is forced into the body while a quantity ofmaterial is loaded in the first tube;

means responsive to arrival of said second ram at said location andcoupled with said control means for rendering the latter inoperative topermit said re ciprocating means to move said first ram toward the bodypast said second position, whereby to pack the loaded material againstthe valve means;

means responsive to a predetermined level of pressure in the packedmaterial in said first tube for rendering said reciprocating meansinoperative to halt the first ram and for shifting said valve means tosaid disposition thereof; and

means responsive to arrival of said valve means at said dispositionthereof and operably coupled with said first ram for driving the lattertoward the body, whereby the packed material in the first tube is forcedinto the head.

15. The invention of claim 14, wherein said control means halts saidfirst ram at said first position for a predetermined period of time tothereby allow ingress of a predetermined amount of material into theport of the first tube each time the first ram is reciprocated.

16. The invention of claim 15, wherein said control means includes amanually adjustable timer for varying said period.

17. The invention of claim 14,wherein is provided means responsive toarrival of said valve means at said disposition thereof and operablycoupled with said second ram for retracting the latter to a positionwhere the port of said second tube is between the body and the secondram.

18. The invention of claim 17,whcrein said retracting means reciprocatesthe second ram between said position thereof and another position wherethe second ram is 13 between the port of the second tube and the body,Whereby a quantity of material is loaded in the second tube whilematerial in the first tube is forced into the body.

19. In an extruder:

an extrusion head having a hollow, generally cylindrical,material-receiving body provided with two inlets in the side of the bodyand an outlet in the base thereof;

a feeder registered with each of said inlets respectively for advancingmaterial to be extruded toward the body and through the respectiveinlet;

a valve including a generally cylindrical housing having an entrance inthe side of the housing and an exit in the base thereof aligned withsaid outlet, said valve disposed in the body for movement between afirst position for directing material through said outlet from one ofsaid inlets and a second position for directing material through saidoutlet from the other inlet;

said housing having an elbow therein extending from said entrance tosaid exit and being rotatable about its axis to register said entrancewith said one inlet when the valve is in said first position and toregister 14 said entrance with said other inlet when the valve is insaid second position; and means operably coupled with said valve andeach of said feeders for alternately operating said feeders and forshifting said valve to the position corresponding to the feeder underoperation, whereby to provide continuous flow of said material throughthe outlet. H 2%. The invention of claim 19, wherein said elbowcomprises a longitudinally curved, tubular member whose longitudinalaxis undergoes a 90 curve between said entrance and said exit.

References Cited UNITED STATES PATENTS 2,366,417 1/ 1945 MacMillan.2,537,920 1/1951 Smith 25l2 2,643,620 6/1953 Miller 10714 2,705,916 4/1955 Millgard. 2,748,933 6/1956 Dutsch. 2,783,499 3/1957 Billen 2515 XBILLY J. WILHITE, Primary Examiner.

